1. Field of the Invention
The present invention relates to an activation mechanism for an optical switch and, more particularly, to a mechanism for moving a reflecting element into or out of an optical signal path between waveguides so as to provide switching of optical signals between pairs of waveguides.
2. Description of the Prior Art
In evolving optical communication networks, the need often arises to switch an optical signal from one path to another. For example, in a network which consists of a number of communication nodes connected sequentially to form a ring, it may be required to temporarily remove one or more nodes from the network. Therefore, the optical waveguides (e.g., fibers) interconnecting the network must be able to "switch" the node(s) from an active (transmit/receive) state to a passive (bypass) state. Many arrangements exist in the art for providing this type of switching. The arrangements may be generally classified into two groups: (1) moving beam switches (arrangements which redirect the optical signal path between stationary waveguides); and (2) moving fiber switches (designs which use an external force to physically change the location of optical fibers entering and exiting the node). The activation mechanism of the present invention is utilized with switches of the former design.
An exemplary optical fiber switch utilizing a moving mirror to perform the switching function is disclosed in U.S. Pat. No. 4,580,873, issued to F. H. Levinson on Apr. 8, 1986. In the Levinson matrix switch, a plurality of mirrors are positioned at the crosspoints of the input and output nodes. As disclosed, a silicon switch substrate is etched to include regions at each crosspoint for holding a rotatable mirror assembly. The application of an electrical signal to individual mirror elements performs the switching function. Although such a switching arrangement may be practical for large array applications, the details of the silicon substrate fabrication process become increasingly time-consuming and expensive for single switch applications.
A remaining need in these and other existing systems is the ability to reduce the overall size, cost, manufacturability and power consumption of the switch.